One method for reducing the fuel consumption of internal combustion engines, in particular vehicles, is start/stop operation, in which the vehicle engines are switched off, for instance, when stopped for a relatively long time in front of traffic lights. As soon as the driver wants to continue driving, the vehicle engine is restarted. The restarting produces unavoidable starting noises, which affect riding comfort. The starting noises are a consequence of, inter alia, the engagement of the starter pinion with the starter ring gear of the vehicle.
In order to reduce the engaging noise and the starting time as well, it is known that the engagement for restarting the engine can be carried out not only after the engine is completely stopped, but rather during its running-down phase. In this manner, the awareness of the unpreventable engagement noise produced by the meeting of the starter pinion and the starter ring gear on top of each other is considerably reduced.
The engagement during the running-down of the engine can only take place at low engine speeds in the range of app. 50 to 100 revolutions/minute. It is problematic that the rotational direction of the engine can change several times during the running-down phase of the engine. This known, final oscillation of the engine during the running-down of the engine is disadvantageous for the engagement of the starter pinion with the starter ring gear, since it may result in engagement occurring during a reversing motion of the engine, which in turn results in a marked jerk of the engine. This jerk stresses the mechanical parts and is perceived by the driver as uncomfortable.
Therefore, an object of the present invention is to provide a method of engaging during the running-down of the engine, which method reduces the stress on the mechanical parts as much as possible and additionally increases the ride comfort of the driver.